In broadband digitized transport systems that simultaneously broadcast signals from remote users via remote units to a receiving station, a plurality of reverse paths simultaneously transmit data to the receiving station. Each digitized reverse path includes a digitized communication link between a remote unit and a host unit. The section of the reverse path that includes the remote unit and the host unit amplifies the signal received at the remote unit. The host unit is in communication with the receiving station. In some cases the host unit is co-located with the receiving station. The transport link can be any type of communication medium such as an optical fiber, a coaxial cable or a free-space optical link.
The signals from a host unit are provided to the receiving station. If one of the digitized reverse paths loses gain, the receiving station will not necessarily be able to determine the system has degraded since the relative drop in power is within the noise level of the receiving station. If the receiving station does, however, detect a loss in gain in one or more of the transport links, the receiving station is not able to determine if the loss is in one of the digital links between the remote units and the host unit, if the loss is in the up-convert path in the host unit, or if the loss is in the down-convert path in one of the remote units.
Thus, one or more of the remote units in communication with a receiving station via a single host unit can experience a degraded communication and the controllers at the receiving station will be unaware of the problem. This can lead to poorly performing transport systems and customer dissatisfaction. Moreover, if the receiving station recognizes that signals received from the host unit are degraded or inadequately amplified, each reverse path is subjected to troubleshooting procedures to determine which path (the digitized communication link between the remote unit and the host unit, the up-convert path in the host unit or the down-convert path in the remote unit) is degraded. This response is time consuming and expensive.
For the reasons stated above and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the specification, there is a need in the art for monitoring gain in remote reverse link radio frequency stages in simulcast architectures.